﻿namespace ProblemsSet
{
    public class Problem_120 : BaseProblem
    {
        public override object GetResult()
        {
            long res = 0;
            for (long a = 3; a <=1000; a++)
            {
                if (a % 2 == 0)
                    res += a * (a - 2);
                else
                    res += a*(a - 1);
            }
            return res;
        }

        public override string Problem
        {
            get
            {
                return @"Let r be the remainder when (a1)n + (a+1)n is divided by a2.

For example, if a = 7 and n = 3, then r = 42: 63 + 83 = 728  42 mod 49. And as n varies, so too will r, but for a = 7 it turns out that rmax = 42.

For 3  a  1000, find  rmax.";
            }
        }

        public override bool IsSolved
        {
            get
            {
                return true;
            }
        }

        public override object Answer
        {
            get
            {
                return 333082500;
            }
        }
    }
}
